A street light is a raised source of light on an edge of a road which is turned on or lit at a certain time every day. The street lights may be high intensity discharge (HID) where sodium (in an excited state) in the case of a high pressure sodium (HPS) lights or a mixture of gases (by passing an electric arc through them) in the case of metal halide (MH) lights are used to produce light. Modern street lights have light-sensitive photocells to turn them on at dusk, turn them off at dawn or activate them automatically in dark weather.
Currently, street lights are inefficient and large amounts of energy are consumed to power the street lights. In addition, street lights are not monitored or controlled remotely. For example, a central office cannot monitor power consumption of street lights or diagnose a street light that fails.